The historical consensus is that Abraham Lincoln was one of the most successful, even "greatest," presidents the United States has had, while James Buchanan who immediately preceded Lincoln, and Andrew Johnson, who immediately followed Lincoln, were two of the least successful presidents in U.S. history. Since the three men dealt with many of the same, but not all, issues, write an essay which describes some of their important differences, actions, accomplishments, and failures. Be sure to comment on all three.